diff --git a/README.md b/README.md
index 7f63641..38ae0ef 100644
--- a/README.md
+++ b/README.md
@@ -104,6 +104,7 @@ Supports adaptive deblocking when transcoding from larger block sizes; this can
 XUASTC LDR supports the following ASTC configurations: L/LA/RGB/RGBA CEMs; base+scale or RGB/RGBA direct; base+offset CEMs; Blue Contraction encoding; 1–3 subsets; all partition patterns; and single- or dual-plane modes. Here is the [XUASTC LDR specification](https://github.com/BinomialLLC/basis_universal/wiki/XUASTC-LDR-Specification-v1.0).
 
 Notes:  
+- Mode #1 (ETC1S) has special support and optimizations for basic temporal supercompression (texture video).
 - Modes #3 (UASTC HDR 4x4) and #4 (RDO ASTC HDR 6x6), and #6 (ASTC LDR 4x4-12x12) output 100% standard or plain ASTC texture data (with or without RDO), like any other ASTC encoder. The .KTX2 files are just plain textures.
 - The other modes (#1, #2, #5, #7) output compressed data in various custom supercompressed formats, which our transcoder library can convert in real-time to various GPU texture or pixel formats.
 - Modes #4 (ASTC HDR 6x6) and #5 (UASTC HDR 6x6) internally use the same unified ASTC HDR 6x6 encoder.